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Master Thesis

Ablation par radiofréquence dans la fibrillation auriculaire paroxystique : étude de l'impact sur la structure et la fonction atriale par IRM

Abstract : Objective: Isolation of the pulmonary veins radiofrequency proved its effectiveness in the treatment of atrial fibrillation (AF). However, very few studies have examined the consequences of this removal on the atria. The aim of our study was to evaluate in combination structure and bi atrial function by MRI. Methods: 37 patients with paroxysmal AF underwent MRI before and 3 months after ablation of the pulmonary veins. Cine sequences evaluated the atrial and ventricular volumes by Simpson method. From these volumes were calculated ventricular function, the active ejection fraction (FEA) and the index of expansion of both atria. Delayed enhancement sequences meant to quantify fibrosis before removal, scarring after ablation and pulmonary venous diameters. Results: The isolation of four pulmonary veins was obtained in all patients, including 22 with a circular catheter and 15 with a conventional catheter. The circular catheter reduce the length of proceedings and half of fluoroscopy (p <0.001) .The patients who had left ventricular dysfunction have all standardized their ejection fraction after ablation (p = 0.01). The left and right atrial volumes were decreased after ablation (p <0.001 and p = 0.007) while the FEA was reduced only on the left atrium (p = 0.02). No pulmonary vein stenosis was objectified. The extent of ablation scars was correlated with the decrease of FEA (P = 0.56; p = 0.01). The recurrence rate over a mean follow up of 9.9 ± 3.9 months was 15%. Conclusion: Our results indicate a decrease in bi atrial volume that seems related to a reverse structural remodeling rather constrictive effect of scars. Moderate alteration of the left atrial contractile function appears directly related to the lesions induced by ablation, because it is found exclusively on the left atrium and is correlated to the extent of scarring. The clinical impact of such contractile alteration remains to be studied.
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Master Thesis
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https://dumas.ccsd.cnrs.fr/dumas-01215461
Contributor : Bu Carreire Université de Bordeaux <>
Submitted on : Wednesday, October 14, 2015 - 11:43:43 AM
Last modification on : Wednesday, August 23, 2017 - 4:30:18 PM
Long-term archiving on: : Thursday, April 27, 2017 - 4:29:25 AM

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  • HAL Id : dumas-01215461, version 1

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Julien Jacquin. Ablation par radiofréquence dans la fibrillation auriculaire paroxystique : étude de l'impact sur la structure et la fonction atriale par IRM. Médecine humaine et pathologie. 2015. ⟨dumas-01215461⟩

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